package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IUserService userService;

    /**
     * 关注或取消关注用户
     * @param id
     * @param isFollow
     * @return
     */
    @Override
    public Result follow(Long id, boolean isFollow) {
        // 获取当前用户id
        Long userId = UserHolder.getUser().getId();
        // isFollow为true，则新增关注信息
        if(isFollow){
            // 新增关注信息
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(id);
            boolean isSuccess = save(follow);
            if(isSuccess){
                String key ="follow:"+userId;
                stringRedisTemplate.opsForSet().add(key,id.toString());
            }
        }else{
            // 若为false，则删除关注信息
            boolean isSuccess = remove(new QueryWrapper<Follow>().eq("user_id", userId)
                    .eq("follow_user_id", id));
            if(isSuccess){
                String key ="follow:"+userId;
                stringRedisTemplate.opsForSet().remove(key,id.toString());
            }
        }
        return Result.ok();
    }

    /**
     * 查询是否关注
     * @param id
     * @return
     */
    @Override
    public Result isFollow(Long id) {
        // 获取当前用户id
        Long userId = UserHolder.getUser().getId();
        Integer count = query().eq("user_id", userId).eq("follow_user_id", id).count();
        return Result.ok(count>0);
    }

    /**
     * 共同关注
     * @param id
     * @return
     */
    @Override
    public Result commonFollow(Long id) {
        // 获取当前登录用户id
        Long userId = UserHolder.getUser().getId();
        // 当前登录用户key
        String key = "follow:"+userId;
        // 查询用户的key
        String key2 = "follow:"+id;
        // 取交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        if (intersect == null || intersect.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }
        // 解析
        List<Long> list = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        // 查询数据库
        List<UserDTO> userDTOS = userService.listByIds(list).stream().map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(userDTOS);
    }
}
